3,3-DICHLOROPROP-2-ENE IMINIUM SALTS (VINYLOGOUS VIEHE SALTS) - A STUDY OF THEIR REACTIVITY TOWARDS NUCLEOPHILES

The title compounds 3 react regioselectively at either the 1- or 3-pos ition depending on the reaction partner. Chloro substitution affording new propene iminium salts is preferred e.g. in the reaction with merc aptans (to 10, 11), amines (to 7, 14, 15), and some activated arenes a nd hetarenes (to 26, 27). Nucleophilic attack at the 1-position provid ing an allyl or allylidene structure is observed e.g. in the reaction with water (to 4), alcohol (to 6), trialkyl phosphite (to 21, 22), tri methylsilyl cyanide (to 30), Grignard reagents (to 31), and acceptor a ctivated methylene compounds (to 33-44). Reaction at both positions wi th heterocyclization to 13 occurs with thioamide functions. The regioc hemistry depends on a complex interplay of several factors in contrast to the FMO predicted orientation. The utility of 3 and some consecuti ve products as versatile C-3-building blocks for further syntheses is foreseeable.